diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/handshake.c | 42 | ||||
| -rw-r--r-- | lib/priority.c | 3 |
2 files changed, 32 insertions, 13 deletions
diff --git a/lib/handshake.c b/lib/handshake.c index 08481cca07..b513872ec3 100644 --- a/lib/handshake.c +++ b/lib/handshake.c @@ -491,7 +491,8 @@ _gnutls_user_hello_func(gnutls_session_t session, uint8_t major, uint8_t minor) { int ret, sret = 0; - const version_entry_st *vers; + const version_entry_st *vers, *old_vers; + const version_entry_st *new_max; if (session->internals.user_hello_func != NULL) { ret = session->internals.user_hello_func(session); @@ -504,17 +505,34 @@ _gnutls_user_hello_func(gnutls_session_t session, return ret; } - vers = get_version(session); - if (!vers->tls13_sem) { - /* Here we need to renegotiate the version since the callee might - * have disabled some TLS versions. We only do it for TLS1.2 or - * earlier, as TLS1.3 uses a different set of ciphersuites, and - * thus we cannot fallback. - */ - ret = _gnutls_negotiate_version(session, major, minor, 0); - if (ret < 0) { - gnutls_assert(); - return ret; + /* This callback is often used to switch the priority string of the + * server, and that includes switching version which we have already + * negotiated; note that this doesn't apply when resuming as the version + * negotiation is already complete. */ + if (session->internals.resumed != RESUME_TRUE) { + new_max = _gnutls_version_max(session); + old_vers = get_version(session); + + if (!old_vers->tls13_sem || (new_max && !new_max->tls13_sem)) { +#if GNUTLS_TLS_VERSION_MAX != GNUTLS_TLS1_3 +# error "Need to update the following logic" +#endif + /* Here we need to renegotiate the version since the callee might + * have disabled some TLS versions. This logic does not cope for + * protocols later than TLS1.3 if they have the tls13_sem set */ + ret = _gnutls_negotiate_version(session, major, minor, 0); + if (ret < 0) + return gnutls_assert_val(ret); + + vers = get_version(session); + if (old_vers != vers) { + /* at this point we need to regenerate the random value to + * avoid the peer detecting this session as a rollback + * attempt. */ + ret = _gnutls_gen_server_random(session, vers->id); + if (ret < 0) + return gnutls_assert_val(ret); + } } } } diff --git a/lib/priority.c b/lib/priority.c index a9f0403d26..afd4b1a680 100644 --- a/lib/priority.c +++ b/lib/priority.c @@ -593,7 +593,8 @@ gnutls_priority_set(gnutls_session_t session, gnutls_priority_t priority) /* set the current version to the first in the chain. * This will be overridden later. */ - if (session->internals.priorities->protocol.algorithms > 0) { + if (session->internals.priorities->protocol.algorithms > 0 && + !session->internals.handshake_in_progress) { if (_gnutls_set_current_version(session, session->internals.priorities-> protocol.priority[0]) < 0) { |